Paleontologists identify new species of mosasaur
Ancient lizard's long, crocodile-like snout suggests it carved out a
niche in a competitive marine ecosystem

Date:
October 7, 2020
Source:
University of Alberta
Summary:
A new species of an ancient marine reptile evolved to strike terror
into the hearts of the normally safe, fast-swimming fish has been
identified, shedding light on what it took to survive in highly
competitive ecosystems.



FULL STORY ==========================================================================
A new species of an ancient marine reptile evolved to strike terror into
the hearts of the normally safe, fast-swimming fish has been identified
by a team of University of Alberta researchers, shedding light on what
it took to survive in highly competitive ecosystems.


========================================================================== Gavialimimus almaghribensis, a new type of mosasaur, was catalogued and
named by an international research team led by master's student Catie
Strong, who performed the research a year ago as part of an undergrad
honours thesis guided by vertebrate paleontologist Michael Caldwell,
professor in the Faculty of Science, along with collaborators from the University of Cincinnati and Flinders University.

More than a dozen types of mosasaur -- which can reach 17 metres in
length and resemble an overgrown komodo dragon -- ruled over the marine environment in what is now Morocco at the tail end of the Late Cretaceous period between 72 and 66 million years ago.

What differentiates Strong's version, however, is that it features a
long, narrow snout and interlocking teeth -- similar to the crocodilian gharials, a relative of crocodiles and alligators.

Strong said this discovery adds a layer of clarity to a diverse picture seemingly overcrowded with mega-predators all competing for food, space
and resources.

"Its long snout reflects that this mosasaur was likely adapted to a
specific form of predation, or niche partitioning, within this larger ecosystem." Strong explained there is evidence that each species of
the giant marine lizard shows adaptations for different prey items or
styles of predation.



==========================================================================
"For some species, these adaptations can be very prominent, such as the extremely long snout and the interlocking teeth in Gavialimimus, which
we hypothesized as helping it to catch rapidly moving prey," she said.

She added another distinctive species would be Globidens simplex --
described last year by the Caldwell lab -- which has stout, globular
teeth adapted for crushing hard prey like shelled animals.

"Not all of the adaptations in these dozen or so species are this
dramatic, and in some cases there may have been some overlap in prey
items, but overall there is evidence that there's been diversification
of these species into different niches," Strong noted.

Alternatively, the main contrasting hypothesis would be a scenario of
more direct competition among species. Strong said given the anatomical differences among these mosasaurs, though, the idea of niche partitioning
seems more consistent with the anatomy of these various species.

"This does help give another dimension to that diversity and shows how
all of these animals living at the same time in the same place were able
to branch off and take their own paths through evolution to be able to
coexist like that," she said.

The remains of the G. almaghribensis included a metre-long skull and
some isolated bones. There was nothing to explain the cause of death of
the specimen, which was uncovered in a phosphate mine in Morocco that
is rich in fossils.

"Morocco is an incredibly good place to find fossils, especially
in these phosphate mines," Strong said. "Those phosphates themselves
reflect sediments that would have been deposited in marine environments,
so there are a lot of mosasaurs there."

========================================================================== Story Source: Materials provided by University_of_Alberta. Original
written by Michael Brown.

Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Catherine R. C. Strong, Michael W. Caldwell, Takuya Konishi,
Alessandro
Palci. A new species of longirostrine plioplatecarpine mosasaur
(Squamata: Mosasauridae) from the Late Cretaceous of Morocco,
with a re- evaluation of the problematic taxon `Platecarpus'
ptychodon. Journal of Systematic Palaeontology, 2020; 1 DOI:
10.1080/14772019.2020.1818322 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/10/201007123105.htm

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